In current broadcasting systems, a Moving Picture Experts Group-2 Transport Stream (MPEG-2 TS) method and a Real Time Protocol (RTP) method are widely used as transport methods for media (for example, refer to Patent Literature 1). For a next-generation digital broadcasting method, MPEG has discussed MPEG Media Transport (MMT) that has been standardized as a new media transport method (for example, refer to Non-Patent Literature 1). Combinations of different transmission paths can be easily used in MMT, which can be used in common for a plurality of transmission paths of broadcasting and communication.
According to the MMT method, both timed media such as videos or sounds that are stream media and non-timed media such as files can be transported on MMT packets. Timed media mentioned here include stream data of main content of broadcast programs, such as videos, audio, and captions. In addition, non-timed media is file data of data broadcasting applications (content), for example, Hyper Text Markup Language (HTML) documents.
Data broadcasting interoperating with a broadcast program is required to be presented in a timely manner. Meanwhile, each of files used in data broadcasting is repetitively transported in a limited broadcasting transport band. Reception terminals can realize timely presentation of data broadcasting by caching data broadcasting files. However, if a reception terminal that is not equipped with an ample cache memory experiences a cache miss for a necessary file, a next repetition period should be awaited, and thus a delay of about, for example, dozens of seconds occurs before data broadcasting is presented.
In a data broadcasting service based on Broadcast Markup Language (BML) in operation at the time of the present application, when an Application Programming Interface (API) that is “LockModuleOnMemory( )” is called out, a specific file can be pre-cached in a cache memory and saved (refer to, for example, Patent Literature 2).